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(No Model.) 2 Sheets-Sheet 1.

A. SIEGRIST.

ROTARY PUMP.

No. 263,975. Patented Sept.- 5, 18 82.

mzwmm 2 Sheets-Sheet 2- '(No Model.)

A. SIEGRIST.

ROTARY PUMP.

Patented Sept. 5, 1882.

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' l UNITED STATES? PATENT omca AUGUST SIEGRIST, or BUFFALO, NEW YORK.

ROTARY PUMP.

, SPECIFICATION forming part of Letters Patent No. 263,975, datedSeptember 5, 1882.

Applicationfiled November 12,1881. (No model.)

To all whom it may concern:

' Be it known that I, AUGUST SIEGRIST, of the city of Buffalo, in thecounty of Erie and State of New York, have invented new and usefulImprovements in Rotary Pumps, of which the following is a specification.

This invention relates to a novel construction of a rotary pump; and ithas for its object the production of a simple and effective pump whichis readily constructed and easily kept in repair.

My invention consists principally of a pump combining in itsconstruction a cylinder .provided with a stationary abutment and wingedpistons, which are seated in a rotating hub,

and which are capable of rotary movement in their seats in the hub, aswill be hereinafter fully set forth.

In the accompanying drawings,Figure'1 is a cross-section, and Fig. 2 alongitudinal section, of my improved pump. Fig. 3 is an end elevationwith the cylinder-cover removed. Fig. 4 is an enlarged end view of oneof the wings of the rotary pistons.

Like letters of reference refer to like parts in the several figures.

Arepresentsthe cylinder; BB, the cylinder covers; (3, the shaft, and D Dtheinlet and outlet pipes connecting with recessed ports E E of thecylinder.

F is the stationary abutment, secured to the inner side of the cylinderbetweenthe ports E E, and having an inner convex face, f, of the form ofa cylinder-segment. The abutment F may be secured in the cylinder by adovetail feather, f, formed on the abutment and fitted in acorresponding groove in the cylinder, or by any other suitable means.

G represents the hub, which is secured to the shaft 0, and H H are twodisks or circular heads, secured to both ends of the hubG by screw-boltsh. The hub is also preferably provided with dowel-pins i, which projectinto openings formed in the heads H H and serve to retain the latter inthe proper position.

K fepresents two or more rotary pistons arranged in recesses J of thehub G ,.between the heads H thereof, and provided with pivots 70, whichturn in bearings in the heads H. These pistons are each provided with asuitable numher of wings, 1, some of which bear against the thecontinuity of the annular space between the hub and the cylinder.Between each pair of wings there is formed a concave depression orrecess, m, which is shaped to fit snugly against the convex face of theabutment F, as

shown in Fig. 1. I The face of each wing Z is composed of a centralcylindrical portion, a, which is concentric with the axis of the piston,

and two end portions, 0 0, which are concencave recess J in the hub, andthe end faces, 0,

bear against the inner surface of the cylinder, as clearly shown inFig. 1. These faces are readily formed by first turning each piston to vthe proper size on its own axis, whereby the entire face of each wing ismade concentric with the axis of the piston, and then arranging thepistons in the hub and turning the projecting portions of the faces ofthe wings down to fit in the cylinder, whereby the end faces, 0, areformed, the remaining portion of the original face between the faces 0constituting the central face, a, as indicated by dotted lines in Fig.4. By constructing the faces of the wings as above described I obtainlarge bearing-surfaces of the wings against the adjacent surfaces of thecylinder and of the recesses of the hub, a close fit of the wingsagainst these surfaces, which are curved from different radii, and areduction in the diameter of the piston.

Assuming the shaft of the pump to be retated in the direction of thearrow in Fig. 1, the liquid will enter the cylinder through the pipe Dand be expelled through the pipe D. In rotating with the hub Gr eachpiston K retains its position until it comes in contact with theabutment F. The latter arrests the movement of the outer foremost wingof the piston and causes the piston to turn on its axis in passing overthe abutment. The recesses m between the wings permit the pistons topass over the abutment and maintain a snug fit of the pistons with theinner face of the abutment until the piston has cleared the abutment.

The wing of the piston which is outermost after the piston has clearedthe abutment projects into the port E, which is sufficiently deep topermit the wing to sweep through it withoutobstruetion until the wingreaches the end of the port, when it is arrested, thereby turning thepiston on its axis and bringing the next foremost wing in contact withthe inner surface of the cylinder. The two outer Wings of the piston nowbear against the inner surface of the cylinder and the inner wingsagainst the surface of the recess in the hub, as shown in Fig. 1, andthe piston retains this position until it comes again in contact withthe abutment, when the above-described operation is repeated.

By reason of the close fit of the pistons against the inner surfaces ofthe cylinder and of the hub-recesses, my improved pump is very efficientboth in it's sucking and forcing actions. This snug fit of the parts ismaintained until the wings of the pistons are so far worn away that theyno longer reach the inner surface of the cylinder. When this happens thepump is readilyrepaired bysubstituting new pistons for the worn-outpistons.

It is obvious that the pipes D D may be interchan geabl y used as inletor outlet pipes, and

that my improved pump may be used as a rotary engine by supplying afluid under pressure to the cylinder through the inlet-pipe.

I claim as my invention- 1. The combination, with a cylinder, A, of astationary abutment, F, secured thereto, inlet and outlet pipes D D,arranged on opposite sides of the abutment, a rotary hub, G, providedwith recesses J, and rotary pistons K, attached to the hub and providedwith wings 1, two of which bear against the inner surfaces of thecylinder and one or more against the recesses of the hub, the wingedpistons being arranged to turn by contact with the abutment,substantially as set forth.

2. The combination, with a cylinder,A, provided with a stationaryabutment, F, and a hub, G, of a piston provided with wings I, havingtheir faces composed of a central portion, n,made concentric with theaxis of the piston, and end portions, 0 0, curved to the radius of thecylinder in which the piston moves, substantially as set forth.

AUGUST SIEGRIST.

Witnesses:

JNO. J. BONNER, EDW. J. BRADY.

